The present invention relates generally to non-contact thickness measurements, and more particularly to non-contact layer thickness measurements and layer thickness variations.
It is sometimes advantageous to measure a thickness of a wet film or layer. For example, when applying paint to a surface it can be advantageous to know the thickness of the paint. Previously, the thickness was not measured until the paint was dry. This way the paint was not damaged or blemished. Waiting for paint to dry in order to measure the thickness of the paint layer can result in excessively long delays and be extremely costly. Some of the equipment for painting, operators of the equipment and parts of the facility in which a product is painted may be idle during this waiting period.
In some instances, the paint is measured when the paint is wet. These previous techniques required the wet paint to be touched. For example, a shim or other similar structure can be inserted into the wet paint to determine the paint layer thickness. This test is not very reliable. Further, the shim damages the paint surface which has to be repaired.